Active filtration is a revolutionary principle of water and sludge filtration. It is applicable in the ecology and highlights the passage from filtration to active filtration.

Active filtration is discovered in the 80’s and it is used to increase performance of the filtration system in order to have a better perfomance of the entire system. Due to motion of the fabric filter on the base of the panel of the sediment material, canals were made in the sludge layer that guarantees better filtration in the liquid material.

Static Filtration

In the sewage disposal, filtration is the process of liquid-solid separation using fabric filter.

Problems with static filtration

The filtration system is very complicated. Fabric filter gets wet and dirty with solid particulate and reduces its efficiency. During filtration, the solid material becomes stratified on the fabric filter shaping a panel.

The thickness of this panel, with time, increases and so the entire process is too difficult and decreases the speed of filtration.


At the beginning of the 80’s Vincenzo di Leo made some filtration tests and observed that moving the fabric filter, at the base of the solid panel, speed filtration increases.

In order to move the fabric filter, there are some techniques. Nowadays one of the most common mathod is to use membranes expandable with blow of compressed air/water.


When the panel of dewatered material is splitted with the motion of the fabric filter, the panel releases the water entrapped within and in all thickness of the panel.

The advantages of this revolutionary technology are:

  1. remarkable decrease for the filtration process
  2. creation on solid panel
  3. Possibility to work with thickness of the panel
  4. Temporay detachment of the solid panel that helps filtration through self-cleaning system


The active filtration is applicabile in the dewatering gravity system and in the dewatering pressure system.

Sectors of use

  • sludge dewatering come from sewage disposal
  • solid-liquid separation in the production cycle (as the production of pigment)

Our Products

Idee e Prodotti s.r.l made Dry Box and Striz Box, used with success in the phase of sludge dewatering: active filtration increases perfomance of the product and facility of use.


Cavenago di Brianza, Square A. Volta, 6, 20873 Italy

Phone +39 02.95335134


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